Kevin T. Coughlin KevinTCoughlin

Profiler

React 16.4 will introduce a new Profiler component (initially exported as React.unstable_Profiler) for collecting render timing information in order to measure the "cost" of rendering for both sync and async modes.

Profiler timing metrics are significantly faster than those built around the User Timing API, and as such we plan to provide a production+profiling bundle in the future. (The initial release will only log timing information in DEV mode, although the component will still render its children- without timings- in production mode.)

How is it used?

Profiler can be declared anywhere within a React tree to measure the cost of rendering that portion of the tree. For example, a Navigation component and its descendants:

Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

	name: CI

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]

	jobs:
	build:

	#!/usr/bin/env bash

	# Define colors
	RED='\033[91m'
	RED_solid='\033[101m'
	GREEN='\033[92m'
	GREEN_solid='\033[42m'
	CYAN='\033[96m'
	NC='\033[0m'
	BLUE_solid='\e[44m'

	{
	"defaultProfile": "{7d04ce37-c00f-43ac-ba47-992cb1393215}",
	"initialRows": 30,
	"initialCols": 120,
	"alwaysShowTabs": true,
	"showTerminalTitleInTitlebar": true,
	"experimental_showTabsInTitlebar": true,
	"requestedTheme": "dark",
	"profiles": [
	{

	import ts from 'typescript';
	import { migration } from '../../migration';
	import { mod } from 'riceburn';

	const inFooJsxTag = (node: ts.Node): boolean => {
	if (!node) {
	return false;
	}
	if (ts.isJsxSelfClosingElement(node) \|\| ts.isJsxOpeningElement(node)) {
	const tagName = node.tagName;

	MIT License

	Copyright (c) 2018 Noel Bundick

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	$version = (Get-Content package.json) -join "`n" \| ConvertFrom-Json \| Select -ExpandProperty "version"
	Write-Host "Version: '$version']"

	node: Platform built on V8 to build network applications
	git: Distributed revision control system
	wget: Internet file retriever
	yarn: JavaScript package manager
	python3: Interpreted, interactive, object-oriented programming language
	coreutils: GNU File, Shell, and Text utilities
	pkg-config: Manage compile and link flags for libraries
	chromedriver: Tool for automated testing of webapps across many browsers
	awscli: Official Amazon AWS command-line interface
	automake: Tool for generating GNU Standards-compliant Makefiles

	package main

	import (
	"context"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"